For Weed Control, Farmers Widen Their Arsenal of Herbicides

They Gain Edge Against Super Weeds but Add to Costs, Environmental Concerns

U.S. farmers are dousing their fields with a wider array of herbicides, helping some turn a corner in the war on super weeds but adding new costs and environmental concerns.

Farmers for a decade have fought weeds that developed resistance to the nation's dominant weed killer, glyphosate, which is widely sold by Monsanto Co. as Roundup. Now they're finding success deploying larger quantities of other, sometimes older herbicides.